Pop icon Madonna is selling off a painting from her personal art collection to help pull in millions for her children's charity.

The 1921 cubist piece, Trois Femmes a la Table Rouge by French artist Fernand Leger, will go under the hammer at a Sotheby's International Realty Affiliates auction in New York City on 7 May (13).

The Material Girl's painting is worth up to $7 million (£4.4 million), and Madonna has vowed to donate all the proceeds to her Ray of Light Foundation and its education projects in Afghanistan and Pakistan.

A statement from the singer reads, "I cannot accept a world where women or girls are wounded, shot or killed for either going to school or teaching in girls' schools. We don't have time to be complacent. I want to trade something valuable for something invaluable - educating girls! Knowledge is power. Let's change the world!"

The 1921 painting, purchased by Madonna at a New York auction in 1990, will be displayed in Hong Kong and London before it returns to the Big Apple to be exhibited in Sotheby's galleries ahead of the sale.